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Ted G.
Ted G., ASE Certified Technician
Category: Ford
Satisfied Customers: 6089
Experience:  20 years auto repair experience, ASE Master Tech, Mechanical Failure consultant, Expert Witness
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2004 F150: a 5.4L V8Has low oil pressure at low RPM.Has some blockage

Customer Question

I have a 2004 F150 with a 5.4L V8
Has low oil pressure at low RPM.
Has some blockage in the lines at low rpm.
Truck runs very well over 800 or so rpm.
Any ideas?
Submitted: 5 years ago.
Category: Ford
Expert:  Ted G. replied 5 years ago.
Any noise from the engine?
Customer: replied 5 years ago.
Engine Clucks away at idle, normal above this rpm.
Expert:  Ted G. replied 5 years ago.
We have been seeing failures to the timing chain tensioner seals cause a loss of pressure in the top end and noise from the lifters and/or cam phasers. If let go it will cause damage to the cam and lifters also.
Ted G. and other Ford Specialists are ready to help you
Customer: replied 5 years ago.
So not sufficient oil getting through because ports are partially blocked?
Is ther a way to flush out/back flush the lines?
Expert:  Ted G. replied 5 years ago.
No they are not blocked, the seal fails and dumps pressure back into the crankcase, so at low volume (low rpms) the engine can't keep up with the leak.
Customer: replied 5 years ago.
So what would be the economical repair choice.
Expert:  Ted G. replied 5 years ago.
If the seals are blown then the valve train and timing components have to be inspected and replaced if necessary. If it is not a long term problem it may just need the seals. But the cams and head journals have to be inspected for damage. If they are too badly torn up then a used engine might be cheaper.